From 21st Century Science and Health:
“Question. What are the requirements of the Science of Soul?
“Answer. The first requirement of this Science is, “You shall have no other gods before me.” This me is Spirit. Therefore, the command means this: You shall have no intelligence, no life, no substance, no truth, and no love, except the unlimited. The second command, you shall “love your neighbor as yourself” is like the first.
“It should be thoroughly understood that all people have one Mind, one God and Parent, one Life, Truth, and Love. The fulfillment of real identities will be realized as that fact is understood. War will cease and true sisterhood and brotherhood will be established. When we have no other gods and turn to no other but the one perfect Mind to guide us, we then experience our God-likeness, pure and eternal, having that Mind which was also in Christ.
“Science reveals Spirit, Soul, as reflected by spiritual beings. Soul is not in a body, but is reflected by spiritual beings. The belief that the eternal reality can be constrained in relative matter is an error that creates problems. A leading point in the Science of Soul is that Principle is not controlled by its idea. Spirit, Soul, has never been confined to human beings. If we reason from effect to cause, we will believe God created mortal humans, and sure enough, physical existence and God becomes a mystery. We cannot interpret Spirit, Mind, through inconsistent perceptions, different for different people. So, improve the thought process; reason from cause to effect and Spirit will be found giving the true mental perception.
“Reasoning from cause to effect in the Science of Mind, we begin with Mind, which must be understood through the idea which expresses it and cannot be learned from changeable ideas. We arrive at Truth or intelligence, which evolves its own complete idea, when we don’t equate reality with human illusions. If Soul sinned, it would be mortal. Sin is mortal because it kills itself. If Truth is immortal, error must be mortal, because error is unlike Truth. Because Soul is immortal, Soul cannot sin, for sin is not the reality of being.
In thinking about this…
A definition for science is knowledge. The knowledge of Soul or Spirit has one intelligence, life, substance, truth, and love. It is content in circular love.
Up against the common images of separate bodies and beings, the knowledge of Soul presents images of one Mind, getting along with constructive purpose. The body of Soul reflects essence and spirit, liveliness.
The body of Spirit has no boundaries. It doesn’t droop. The body of Soul embraces sinless cause and effect. The knowledge of Soul naturally eliminates human illusions and emotions because Soul’s ideas are substantial.
 Ex. 20:3; Deut. 5:7
 Matt. 19:19, 22:39; Mark 12:31; Luke 10:27; Rom. 13:9; Gal. 5:14; James 2:8